for the combat update whe know the banner shield add knockback resistance but this is more interessing if whe going with spetial hability conected with the color and the patern of the banner (for exemple black shield added he short bliness effect or he shield with skull paterne added wither for 2 sec on the enemy but need to be reload he long time, monjang paterne can be also added he 2 heart in the healt bar(not extra healt just the forgetten healt booster effect) temporaly)

yes whe also already have lot of magic type in minecraft enchenting, alchimist , soup ,golem,beacon, (redstone?) ect... but maybey not